Microsoft chief executive Steve Ballmer's pay package fell 4 per cent after his bonus was trimmed partly due to slower-than-planned progress in the software company's online business and a drop in revenue at its Windows division.

According to a securities filing on Tuesday, Ballmer's pay dropped to US$1.3 million ($1.6 million) from US$1.4m in Microsoft's latest fiscal year through June.

Ballmer, 56, got a performance-related bonus of US$620,000, down from US$682,500. His salary was little changed at US$685,000.

The Associated Press' calculation includes salary, bonus and other all other compensation received by Ballmer. He voluntarily did not receive any stock awards.